Dear all Numista friends thanks for your opinions! Yes, I am even more convinced now that this is a fake coin. Most probably a contemporary fake, faux d'epoque, which has seen circulation during its time. I bought it in a lot with other genuine coins, and not a great loss for me.
Andre, the rim is not like on your coins, in some places it has traces of reeds, but on the majority no reeds, I am convinced this is a cast fake coin made to circulate, either in poor silver, or copper washed with silver. Interesting from the historically point of view, unless anyone collects contemporary fakes. Its weight is 5.60 gr, compared with Numista data 6.68 gr.
As some of you may know, I am focused on Austrian Empire coins, and have come to a conclusion that those coins were among the most faked ones for its period! I will post later a couple more Austrian Netherlands Kronenthalers for you to see!
But I have another 20 Kreuzer 1815, which I asume to be genuine, although worn, and its weight is only 4.61 gr How about this one?